This sort of stuff (and a lot of other popular things) highlights something that I've felt for years: we are still so far away from a good ops story as an industry. Why would someone use this? Because they only want to deal with "one thing" in production. Dealing with multiple stacks is annoying. People show stuff like kubernetes as a way to handle multiple stacks. That stuff is also complicated. There is still a hug…
However I doubt shoving everything into the DB will get us there - besides some hardcore PG enthusiasts like OP & co.
Sqlite together with the application layer of your choice seems to make much more sense to me, but hey we don't have to all like the same stuff (better we don't).
Also without reading too much in detail but I wonder how testing/monitoring etc would be supported